Pressure responsive switch operator



y J. Loma Y* 2,057,387

PRESSURE RESPONSIVE SWITCH OPERATOR Patented Oct. 13, 1936 PATENT OFFICE PRESSURE RESPONSIVE SWITCH OPERATOR Joseph H. Loeb, Morgan City, La. Application January 15, 1935, Serial No. 1,943

1 Claim.

This invention relates to a pressure responsive switch operator in ,a signalling device for pneumatic tires.

An object of the invention is the provision of i a switch operating mechanism for a signalling device for indicating to a driver that a low pressure exists in a pneumatic tire of the vehicle so .that the operator of the vehicle may take the necessary steps to correct whatever condition exists in the tire that is causing the low pressure.

Another object oi the invention is the provision of a switch operating mechanism for closing an electric circuit to cause audible or visible signais, the circuit being closed automatically and periodically through the intermediary of a. plunger or rod which is projected into the path of a switch-operated mechanism, said plunger or rod being released to an operative position when the air pressure in the tire has been decreased to u a predetermined degree.

A further object of the invention is the provision of switch operating mechanism for a signalling device for pneumatic tires which is simple, eillcient and readily applicable to a rim of a u vehicle wheel the device being adapted for attachment to the rim without necessitating any changes in the construction of the wheel or rim. This invention will be best understood from a consideration of the following detailed descrip- .o tion, in view oi the accompanying drawing forming a part of the speciilcation; nevertheless, it is to be understood that the invention is not conilned to the disclosure, being susceptible of such changes and modifications as denne no ma- 35 terial departure from the salient features of the invention asv expressed inthe appended claim.

In the drawing:

Figure 1 is a fragmentary vertical section of a wheel and oi the switch operating mechanism 40 shown in operative relation with a switch.

Figure 2 is a horizontal section taken along the line 2-2 o! Figure 1,

Figure 3 is a vertical section taken along the `line3i3ofFlgure1,and 5 Figure 4 is a vertical section of the switch operating mechanism with the switch removed,

' Reierring more particularly to the drawing, L3 designates a vehicle wheel having a rim Il which consists of a pair o! outwardly flared 50 flanges l2 and a base member I3 located inwardly of the peripheries ot the anges I2 whereby an annular channel is formed in the rim. A brake drum Il of the usual type` is associated with the wheel III.

A casing I5 has its free edges I6 located with- (Cl. o-58) in the annular channel I1 of the rim Il. An inner tube I8 is located within the casing I5 and has one portion I9 when iniiated forced between the free edges or beads I6 of the casing I5 and in contact with the base member I3 of 5 the rim II.

A casing 20 which may be of any conguration in cross section extends transversely oi' the rim I I and is normally disposed in a horizontal position. This casing has an extension 2l formed 10 integrally with the casing 20 and is provided with a reduced portion 22 received within an opening 23 formed in the rim II in Order to prevent rotation of the casing 20 and its extension 2| in the opening 23. The extension is prol5 vided with a web 24 received within a complementarily formed groove 25 extending laterally Ifrom the opening 23. The reduced portion 22 of the extension 2| provides a shoulder 21 which engages the inner face of the base member I3. 20

A tubular member 28 neatly fits within the extension 2l and is provided with a flange 29 resting upon the outer edge of the reduced portion 22 and the outer face o f the base member I3. The inner end of the tubular member is threaded 25 to receive a cap nut 30. A washer 3| is located between the cap nut and the inner portion of the extension and the casing 20. The cap nut in connection with the flange 29 not only secures 'the tubular member 28 in place but likewise the 3U casing 20 and its integrally formed extension 2l. 'I'he tubular member 28 is provided with an upstandingannular flange 32 projecting from the iiange 29 to provide a pocket to receive a head 33 oa pin 34 which is disposed centrally of the 35 tubular member 28.

A diaphragm 35, which may be formed of leather or any other suitable substance, is stretched across the outer end of the upstanding ange 32 and hasits side walls secured to 40 the flange by means of a split ring 36. 4The inner tube I8 when inated presses inwardly upon the diaphragm for maintaining the head 33 oi.' the pin 3l upon the lateral ange 29.

Projecting into the path of the outer end of the plunger 19 which will be presently described, is a spring arm 5I which passes through a perforation 5Iit in a rock shaft 52 mounted in a casing 53 carried by a bracket 5I which is adjustably secured by means of a bolt 55 to the brake 60 drum I4. The spring arm, asshown at 52 is secured to the casing 53. A washer 56 is located between the lower end of the bracket 5l and the drum I4 and is provided with ears 51 to engage over the beaded edge 58 of the drum Il. A bolt I5 rod 'I8 which projectsthrough .oneendofthecasing28. Thisrodhasitsinner lThe rod, projects through 55, through an elongated slot 59 at the lower end oi' the bracket 54,' permits adjustment of the bracket towards and away from the center of the vehicle wheel and also permits the bracket to be revolved on the bolt to properly position thearmil in thepathofthe free end ofthe plunger I5 when the wheel is revolved.

A cam 58 is located on the outer end of the rockshaftnandisadaptedtoengageaspring contact member 8| which forces said spring contactmember into a stationary contact- 82.

Wires (not shown) lead from the stationary conand the movable contact 5| to a light ontact 82 the dash (not shown) which will be periodically illuminatedas will be presently explained.

The casing 28 has an enlargement 55 adjacent the free end of the rod 52. A lever 58 is pivotally mountedatllwithinthecasingnandhasone end connected at 58 to a lever 88 which is pivotally connected at 'Il to the outer end of a slidablymountedrod'li whichhasabearingina bracket 12 formed in with the casing 20. the slot Il and the free :nd is within the tubular meme ber 2 lA bell crank, pivoted at 12 on the casing 28,- has a short arm 'Il pivotalLv connected at -18 with the reciprocating rod A long arm 'l5 ofthebellcrankhasanend 'Il passingthrough an elongated opening |1 formed in a plunger or an opening 19 in emi mounted in a bracket 88 and in connection with the walls of the openings 18 provides bear'- ings for said plunger. A-coil spring 8| embraces the rod 1| and has one end in engagement with the bracket 'I2 and the other end in engagement with a collar 82 xed on the rod"|| adjacent the pivotal point 'l'he operation of the device shown in Figs. 1 to 3, inclusive, is as follows: It will be noted that all of theparts are so-constructed that the device may be readily assembled and attached to the rim of the vehicle wheel with facility. 'Ihe only change in the\rim necessary to apply the ievice is to provide theopening 28 for the insertion of the reduced end 22 of the extension 2|. After the extension 2| and the casing 28 have been applied to the rim the tubular member 2l is inserted into the extension 2| from the exterioroftherimandthecap nut88 rigidly securesthepartsin place. Itwillbenotedthat the slot M and the tubular member extends entirely through the inner end of the tubulax meinber28sothatthelever maybereadilyinserted through the bottom from the inner end of said tubular member.

Inrnzures1andiimpartsare'showninpoeinen with the inner tube la inflated end the device is then in an inoperative position with the inner tube pressing upon the diaphragm I5 for maintaining the irmer end of the pin 34 in engagement with the inner end of the lever 88 so that the rod 18 will be in a retracted position against .the tension of the spring 8|.

When the inner tube I8 loses air and becomes suillciently deflated the pressure against the diaphragm 35 will not be sumcient to overcome the tension of the spring 8|. Therefore, the plunger 'I8 will be moved outwardly by the spring 8| acting on the collar 82 for. forcing the rodt'H outwardly and thereby oscillating the arms 14 or the bell crank so that the arm is oscillated which moves in the slot causing the plunger 18 to be moved outwardly into the pathof the spring arm 5|.

'I'he lever 66 has its outer end moved downwardly while the inner end which is within the casing 28 will be moved upwardly, raising the pin 84. K

With the plunger 11 disposed in an outward position it will engage the spring arm 5| causing rocking of the member 52 periodically ,with a periodic closing of the alarm to notify the operator of the car that the tire is being deflated.

' After the tire has been xed and the proper pressure has been placed in the tire, the pin 84 will be forced inwardly against the inner end of the lever 85, thereby raising the outer end of the lever and causing the link 69 to move the rod 1| inwardly against the tensionof the spring, vwhereby the bell crank will move the plunger I8 inwardly and out of the path of the spring arm 1|.

I claim:

An operating mechanism for tire signalling devicesl comprising a barrel carried by the rim of a pneumatic tire, a casing connected to the barrel, a lever pivotally mounted in the casing and projecting into the barrel, a plunger in the barrel and acted on by a predetermined pressure in the tire for retaining the plunger in operative relation with the lever, a rod slidably mounted in the casing and having an end adapted to be projected beyond the casing for causing operation of a circuit breaker, an auxiliary rod slidable in "the casing. a spring urging the auxiliary rod in thdirection ofl movement of the first rod, a link pivotally connecting the outer end of the auxiliary rodwith the lever, a bell-crank pivoted in the casing having an arm pivoted to the outer end of theauxiliary rod, the other arm of the bell-crank having operative connections with the rst rod so that when the lever is released the spring will urge both rods outwardly.

Jos. H. LoEB. 

